The present invention relates, in general to circuits and, more particularly, to mixer circuits for providing frequency translation.
Conventional dual band cellular phones have two separate receiver circuits for receiving modulated signals at two different carrier frequencies. For example, a conventional dual band cellular phone has first and second receiver circuits for receiving modulated signals having carrier frequencies centered at 900 megahertz (MHz) and 1900 MHz, respectively. Each receiver circuit has its own separate mixer for translating the carrier frequency of the received modulated signal from the Radio Frequency (RF) range to a signal having a frequency in an Intermediate Frequency (IF) range.
Employing two separate mixers for generating IF signals increases the amount of die space needed and increases the power consumption of the cellular phone. As demand moves toward smaller, less expensive phones, this approach of employing two separate mixers is undesirable.
Accordingly, it would be advantageous to have a mixer circuit and method for frequency translating incoming modulated signals in a dual band phone. It would be of further advantage for the mixer circuit to have low power consumption and a minimum number of components.